Author Topic: TLO71 replacement with TLO72  (Read 547 times)

Plaid63

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TLO71 replacement with TLO72
« on: March 28, 2022, 07:49:15 AM »
Apologies to begin with. Noobie builder here. I'm about to put together a Fritter pedal. I've got TL072 dual op amps on hand. Can I use one in place of the TL071 single op amp?
TY!

jimilee

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Re: TLO71 replacement with TLO72
« Reply #1 on: March 28, 2022, 08:06:09 AM »
Nope, the 71 is a single opamp the 72 is a dual. Different pin outs. What else do you have?


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Plaid63

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Re: TLO71 replacement with TLO72
« Reply #2 on: May 02, 2022, 10:23:16 AM »
Jimilee, Just now seeing this. Thanks for your response. The build was a success once I put in the 71.

I'm off to a great start with 8 builds but still have a gob load of questions. I'll get back to you with them if you have the time.

One thing I'd like to build is the VFE Yodeler. I'm thinking I might be able to slog through it at this point. Thought I'd seen the pcb of the Yodeler on Madbeans at some point. Any knowledge about this?
Cheers

jimilee

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Re: TLO71 replacement with TLO72
« Reply #3 on: May 02, 2022, 11:02:00 AM »
Jimilee, Just now seeing this. Thanks for your response. The build was a success once I put in the 71.

I'm off to a great start with 8 builds but still have a gob load of questions. I'll get back to you with them if you have the time.

One thing I'd like to build is the VFE Yodeler. I'm thinking I might be able to slog through it at this point. Thought I'd seen the pcb of the Yodeler on Madbeans at some point. Any knowledge about this?
Cheers
I believe you are correct. Reach out to him to see if he has any.


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Plaid63

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Re: TLO71 replacement with TLO72
« Reply #4 on: May 03, 2022, 01:03:25 PM »
Got a couple more questions for you. I've seen a couple of mentions about using a C1K instead of a B1K due to the different taper with some fuzz boxes. Is that a standard sort of replacement with a fuzz or for very specific fuzz pedals?

I'm building a pedal that requires a 1uf cap. I only have a filter cap. Can that be used in its place and if so does the polarity (orientation on the board) make a difference.

Thanks for your time
Charlie

jimilee

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Re: TLO71 replacement with TLO72
« Reply #5 on: May 03, 2022, 02:05:06 PM »
Hey hey. Its not really indicative of a fuzz pedal, really. A C taper is reverse, so youd want to use an A taper. The problem with this is, most of the rotation wont do much until you reach the end, then all the changes will be bunched up at the end. B taper is usually the norm.

For your other question, I would need to see the schematic.


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Plaid63

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Re: TLO71 replacement with TLO72
« Reply #6 on: May 04, 2022, 06:04:30 AM »
Cool, B taper it is then.

The 1uf cap scenario is on the Tower Overdrive from pedalPCB. If you have a moment can you take a look.
TY!!!

Drew Hallenbeck

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Re: TLO71 replacement with TLO72
« Reply #7 on: May 04, 2022, 08:25:45 AM »
Cool, B taper it is then.

The 1uf cap scenario is on the Tower Overdrive from pedalPCB. If you have a moment can you take a look.
TY!!!

I just looked at the schematic for the Tower Overdrive, I'm guessing the cap you're asking about is C5?
If so, you can use an electrolytic cap there with the positive side toward the opamp.
FWIW, I typically try to stay away from using electros in the audio path as much as I can. When it is required, I'll try to order "audio grade" caps to use there.
You very well may not even notice any difference and a regular old run of the mill electro might work just fine.
I'd suggest using a socket. Add the 1uf film cap to your next order and swap it out later.
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Plaid63

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Re: TLO71 replacement with TLO72
« Reply #8 on: May 04, 2022, 08:38:56 AM »
Excellent advice. I've got a WIMA cap in my Tayda cart so I'll hold off till it's in.

I took your advice and emailed Brian. He said he has a Yodeler pub that Peter Rutter gave him and may put a new version of it up at some point.

Cheers